The fall followed roughly 1 percent gains on both Monday and Friday after the Federal Reserve held U.S. interest rates steady last week and as investors continued to fret about Chinese economic growth.

“This sort of activity is like a waltz, you’re going back and forth,” said Irwin Michael, portfolio manager at ABC Funds.

“It’s a no-bid market. There are not many buyers out there,” he said. “It’s volatile, but it’s a tug of war.”

The Toronto Stock Exchange’s S&P/TSX composite index .GSPTSE ended the session down 288.35 points, or 2.09 percent, at 13,491.09. All 10 of its main sectors fell.

Gold, copper and U.S. crude oil prices fell, hit by a stronger U.S. dollar and persistent demand worries, particularly out of top resource consumer China. The declines sent the Toronto index’s materials group, home to mining stocks, plunging 4.4 percent.

The most influential mover was Valeant Pharmaceuticals International VRX.TO, a large weight and an erratic stock, which lost 5.4 percent to C$287.17.

The materials decline was echoed by the remaining nine key sectors, with energy sliding 1.7 percent and the hefty financials group, which has considerable exposure to resource companies, also retreating 1.7 percent.

Toronto-Dominion Bank (TD.TO), fell 2.1 percent to C$51.50, while Royal Bank of Canada (RY.TO) lost 1.7 percent to C$71.88.

There were 208 decliners and 37 advancers, for a 5.62-to-1 ratio on the downside. The index posted three new 52-week highs and 11 new lows.

“This market has done this before. You really don’t have to have a major reason - once the selling starts, it accelerates. And the buying is the same,” said David Cockfield, managing director and portfolio manager at Northland Wealth Management.

“It’s volatility and a tendency for people trying to follow the market rather than just invest ... they jumped all over the mining stocks.”